Hey guys, im in the middle of an engine project. and needed a little bit of your opinions. I am building a .40 over 350 stroked to 385 w/ short rods and a California Automotive crank. I bougth the vortec heads stock.

My questions are as follows. (question #1)What cam should i get i will be stalling at around 2300 rpms and it will be an everyday driver. But im a guy that can live with an everyday open header race car to go to work and back. I was thinking the xe268 but i thought it might be to small. i never intend on reving past 5500rpms. I also saw a magnum cam. which kept the lift safe with the heads(474) and had a duration of 230, 234.

question #2)What kind of size dish pistons should i have to keep the comression streetable. also with this much duration will i be able to get 10 to 1 compression on iron heads. ?? Im sure with the magnums duration and lobe sep of 111 it might be ok. Do you think that might be to much cam even for the cubic inches.???

I will have it done in around three to four months. After that i will dyno it and put up the results.

Thanks again guys!

 

Oh yeah what kind of ET do you guys think i will run with it on my camaro. hehe

 

Nobody wants to talk to me!!!

Please, you guys imput is very important to me!

 

I'd skip the Magnum cam and get an Xtreme-Energy hydraulic roller retrofit grind. The lobes are much more advanced and offer more agressive ramps.

You havent specified enough stuff. Is this an engine that will retain emissions? Is it going to be fuel injected or carburated?

What's your final drive gearing? Are you using a 700R4 transmission, or something else?

You are using the Vortech heads which implies an Edelbrock manifold and carb. With that implication, I'd hazard a guess that a cam profile like the XE268 would be about what I would choose. A 230/234 duration cam? Well, if you wanted to use that one, I'd suggest you clean up the Vortech ports a little to improve the 5500 - 6000 RPM operation. Also keep the lobe separation angle to around 110 degrees.

As for the piston question, you need to figure out what your intended installed deck height is going to be as well as the thickness of the head gasket. Once you decide on these two things, you can figure out which piston to use. Since they are iron heads, I'd suggest keeping the compression ratio between 9.5:1 and 9.75:1 if you are going to carburate it.

I'm using Lunati lightweights in my 385 project. It's using race ported aluminum heads, TPIS Miniram, speed density ECM, and a custom 230/236 degree cam on a 112 LSA. It'll be about 10.75:1 c.r. but benefits from the thermal barrier coated pistons and combustion chambers, as well as the superior fuel distribution of port fuel injection.

Funny, my 385 was going to be a Vortech, externally balanced short-rod engine too, complete with the XE268 grind in roller-retrofit. Then I found this stupid Miniram and "project creep" set in.

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First off, if you are using the stock Vortec head, you have a replacement truck head, not a performance head, regardless of the flow numbers. Keep that in mind for the next few minutes.

There's a reason that the XE268 is such a popular choice with those heads. It's the biggest, best cam you can put under those heads as they come out of the box. You'll get more power and better driveability from that one than you will from the Magnum cam, which is an older design (the best of its time) that has been upstaged by the newer ones.

Those heads, not being a performance head, are not set up for a high lift cam. Numerous people have reported that the reatiners hit the valve guides at about .480" of lift. So to use nore cam than the XE268 you need to get the valve guides machined off.

Next, since they're not a performance head, they have regular pressed-in studs. These are notorious for coming out when used at high RPM, high spring pressures, aggressive cam ramps, etc. So your next machine work would need to be to fit them for screw-in studs and guide plates.

Next, since they're not a performance head, and they don't support lift over .480", the springs that come on them are the regular stock 1.25" diameter crap. So even if you do machine down the valve guides, you can't put springs on there that will support above .500" of lift, without machine work to the spring pockets. So there's some more money you need to spend on machine work. At least the XE268 will work with the stock-size springs, although certainly not with the ones that come on the heads.

Next, since they're truck heads, they have very ordinary valves. Any good performance head build-up would use thin-head valves with undercut stems for light weight and high flow, and they would be made of some high-durability grade of stainless steel or titanium or something; but the ones that come in those heads are just plain, common, ordinary, stock, truck valves. So you'd need about $200 worth of valves to get the benefit of added flow from a higher-lift cam.

By the time you do all that which is more or less required to use any more cam than the XE268, you have already spent more than the cost of some S/R Torquers, nearly as much as Edlebrocks, etc. In other words, those "budget" performance heads aren't a deal any more.

So it would be wise to make up your mind before you buy anything: either it needs to be a Vortec motor with a Comp XE268 or less, or it needs to have some other kind of heads.

AND BTW - maybe you can live with open headers on the street, but all the rest of us aren't the least bit interested in having to listen to that racket driving past our houses. It's obnoxious as hell. Keep it at the track where we all enjoy it, and put an exhaust system on it for the street where the noise is unwelcome.

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"So many Mustangs, so little time..."
ICON Motorsports

 

The race car open header thing was an exageration to get my point across. I dont mind a few shortcoming. Open header race cars would annoy me.

I probably should have stated a little more about my build up. This is not going to be a race engine. It does not need to meet emmissions. I am interested in around 380hp and around 400lbs. if i get more then thats good but not needed. I wanted to know how do you guys thing the engine will behave with the 268 cam. I never intend on reving past 5500. To much of a stock bottom end. I just dont want the cam to die out a 4500rpm. I know it wont on a 350 but i have more ci. If it looses all power above 5500 that is just fine. I want it as a torque monster and nothing else. The car has a 3.42 rear end posi. a 700r4. Carburated..750cfm.

I just wanted to know what you guys think it will do. I am not after a race engine. Otherwise afrs would have been in the buildup.
Again thank you guys for giving me any imput you might have

 

I think from what I've seen elsewhere that those heads and the XE268 cam are very happy together... I don't think you could go wrong that way.

I had their XE274 for a while in my 400, with maybe somewhat better heads than those, it was a seriously high-torque thing. It did 284 RWHP and 373 RW ft-lbs with a Performer not RPM intake and the L69 air cleaner installed and operating... that works out to about 440 ft-lbs at the crank... do you think that would be satisfactory in your case? Your build ought to put up numbers not too far from that.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

I have the XE-268 in my car with the vortec heads. I am not using stock springs or the press-in studs. If you don't plan on revving past 5500 RPM get this cam or something smaller. Especiallly if you drive it everyday. My compression is 10.9:1 and I use the Air Gap Performer RPM intake. This thing wants to rev way past 6000 RPM. I am using 1.6 roller rockers and the the valves have 5 angles and are back cut 30 degrees. I also pocket ported them before I put them on. It seems like when it hits 4000 nitrous kicks in. This setup loves the high RPM's.

You might try the XE-262 for daily driving. You will definitely need a torque converter with the 268. I tried to use my stock one while I saved up for a 3000 stall. I hated it. I had "Neal Chance Racing" build me a 10" that is supposed to stall at about 3000 to 3200. I am using 3.73's and a non-lockup 700r4.

 

I'm running the 262 and wish I had a little more. The 268 looks about right to me, and others have had good luck with it with stock Vortecs. Especially with the 385 you shouldn't have any problems with the driveability and such with the 268 I wouldn't think...

I'm running a Darrel Young 2200-2400 rpm stall converter on mine BTW. Good converter for $199...

If you hadn't already purchased the Vortecs the Hi-Perf units that Scoggin Dickey sells would have been the way to go. They are clearanced for more lift and have bigger springs to handle around .550ish lift. They run around $600 last I saw, still well under any comparable head. You can also get them with screw in studs for like another $100. That's still cheaper than something like S/R Torquers, which the Vortecs outflow by a bit. Of course for another $150ish you could have the TFS 23 degree heads so...

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

 

Ok will i need new springs with the 268. :>
What do you think it will do in the quarter?

If you guys tell me better than 13.1 i will be very happy.

To the guys that replied, thank you very much I really apreciate it.

 

i ran a 13.8 at 102, 2.2 60', on my 305... to give you an idea, it dynoed around 260RWhp, and i have the wieght on my car down to 3400 with me in it, full interior and spare...

I would say that to have 300 RWhp will probably get ya into the 12's... But it all realy depends a lot on your gearing, and suspension etc.

Steve

 

In the Sept. issue of Car Craft they produced 442HP @ 5900 RPM and about 450lb.ft. of torque @ 4400RPM. Now that's after some fine tuning that can only do with a dyno, but even on there first run with 1.5:1 stamped steel rockers, and a "outta the box" Edelbrock 750 cfm carb, they got ~420HP.

The heads were from www.SDPC2000.com and were already set up with springs good for .550" of lift. They're about $650. I don't know about the screw in studs though.

They used a Comp Cams XE-274, Edelbrock Performer RPM, flat top pistons for ~9.5 compression, 1.6:1 roller rockers, and a 1" carb spacer.

They said the Edelbrock carb ran a little lean so they changed metering rods to a smaller size. Now keep in mind that it may have run a little lean for max HP, but I'm sure it'd be fine for the street.

As RB said, that's up there around the price of the S/R's. The S/R's have a thicker deck, come ready for .500" lift, screw in studs, 2.02"/1.60" valves, and are a DIRECT bolt on. You don't have to buy a new intake, etc. And they flow about as well as the Vortecs UNMODDED!! If you pocket port them you can look at another 20HP gain. And they're only $100 more.

According to Ray, if it's $100 more to get the screw in studs, then "hands down" the S/R's are the clear winner IMO.

AJ

 

I don't have times, or hp numbers for my setup, but with the cam below, the car runs excellent. I'll give in to RB, these are truck heads. But they are also the best flowing 23* head that GM has ever put onto a standard SBC. THe 268 should run very well. The 385 will make a lot of torque, so you don't want a high winding cam. I would get the 268 if I were in your shoes.

 

Don't any of you KNOW any machinists? :hail: "side jobs"

 

I REALLY REALLy doubt that S/R will make equal power to the vortecs, just becuase heads flow similar #'s doesn't mean they will make the same power. For everyone that says for the price of modified vortecs you can have "real" heads that make "real" power that is such bull****. I have some ported vortecs on my firebird (half the porting job was FREE.............DIY, friend did the professional porting for free as well) and with the 284 extreme energy cam, its a SOLID mid 12 second car that tears a new A-hole to all the AFR and Trick Flow equiped 350 powered cars with similar setups that I've raced. In fact I raced an AFR 190 headed 284 extreme energy cam 383 STROKER motor 71 chevelle in the camaro tonight, he had 3.73 gears and a Th350, I raced him in the camaro and he just BARELY beat me by like 1.5 car lengths. Whenever I race my firebird versus my camaro I slaughter it by like an 1/8 of a mile, like the camaro is in reverse or something.

If you want awesome power at the cheapest price, the trick is to try and do everything you can yourself, and only get the absolute BARE minimum machine shop work done, cuz thats where the cost kills ya. If you can get good cheap machine shop work and figure out how to cut valve stems for valve seals yourself (which I did with a drill press) then vortecs are UNBEATABLE for the price for building a 12 second car. Thats a bold statement, but I stand by it. If anyone wants to bring an aluminum headed similar cammed 350 carbed thirdgen to Tucson and say otherwise, I'd be glad to make a few 1/4 mile passes down Kolb to prove otherwise

 

ChrisFormula... get that car to the track! Sounds like it will put down some awesome numbers.


I'd just like to point out that there are a couple companies offering 1.25 dia springs that fit vortec and support .500+ lift without machining.

machining screw in studs would still be a good idea.

for AFB camaro to run 12's would probably be a bit of a traction challenge, the vortecs make really good torque, with 385 CI, you will have that much more. I can see 12's in your future with a 268XE

I have the 262 in my car atm and like ray, I wish i had a bit more also.

I'm curious, how some people refuse to regard the vortec has a performance head.. they out flow LT1 aluminums..
LT1 heads musn't be performance heads either
Vortecs have a unique chamber design that not only promotes and efficient swirl in the combustion chamber, but also places the spark plug more toward the center. Look close inside the intake port and you'll also see an air diverter in the casting around the valve guide, which splits and straightens the airflow around the back of the valve, helping reduce the effects of valve shrouding.
Many of the cheaper 'performance heads' are a lot more basic in their chamber and port designs.

 

"I'm curious, how some people refuse to regard the vortec has a performance head.. they out flow LT1 aluminums.."

Thats mainly because "some people" don't have Vortec heads.


A "performance head" in every sense of the word .

 

The Vortec heads simply aren't a "performance" head. A "performance head" doesn't come with pull-out studs, the weeniest valve springs on the planet, and valves that weigh about a pound apiece.

Like I keep saying, everything about those heads except for the flow numbers is strictly low-performance. They're a replacement truck head. But, an extremely high-flowing one. Unfortunately they suffer from the same problem as any other stock high-flowing head; to make them into a real racing head, you have to spend so much money on them that by the time you turn them into a race piece (distinct from a "fast street car" piece) you have as much money tied up in them as you would in a set of real race heads, and you have lost their single biggest advantage besides the high flowing ports: their price.

Like I also keep saying, the way to use them effectively is to work within their limitations; pick a cam and a RPM range where you don't need bigger valve springs or lighter valves, and the pull-out studs are adequate, and don't try to go any farther than that with them. They can give you, as people like Chris can tell you, a fast as hell street car at a really good price. But, try to go beyond their built-in limits, they're subject to the same economic laws as any other head.

It's all about $$$ per HP. Up to a point, the HP comes real cheap. Then suddenly they start getting alot more $$$ for each one. The goal is to find the sweet spot of the most HP for the least $$$, and the way you do that is to avoid machine work as much as possible.

 

I have the GMPP Fastburn Aluminum Vortec heads. Would you call these performance heads or what. They have screw-in studs, lightweight valves, etc.

 

Yes, or what.

Those aren't the ones everybody is talking about. Those are designed, built, and sold for performance applications. They are not the replacement truck head that people want to make a budget street screamer out of.

 

I know they are performance heads and I paid lots for them but they do work well. What I was trying to get across is GM does make a couple of Vortec style heads. This thread about a 385 Vortec headed monster might be confusing some with the GMPP Fastburn 385 engine that uses the aluminum Fastburn heads. I wish when people post stuff about Vortec heads they would make it clear which ones they are talking about.

 

I challenge you to take a good close look at a set of vortec heads. Their flow numbers are actually an underrating of their potential. The vortec's port design, chamber design are superior designs over heads costing twice as much money.
They aren't simply a head that flows well, they are a well designed peice of GM engineering.

Are they the end all in performance? heck no, and I agree that after a certain limit, the vortecs are best replaced with a high $ aftermarket head.

vortecs are cheap, and in some area's a built cheap, the springs and press in studs for example.

But I definatly consider them a mild performance head.

a head that can produce 400+hp without port work, and a sub .5 lift cam definatly isn't just a smogger head.

 

My Opinion?

I'd like to let ya un against my GTA, 350, vortec heads...

Sure you might call them a replacement truck head, but then why do they get pushed as a quasi performance head?

Everything about these heads is performace, minus the top side. Some of the stuff you can get away with until a point, there are valve springs that can support the bigger lift...


These heads are a great set, and yes, i would dare say they are a performance head. I do not agree with the fact that these heads lose there potential in the $$$ per HP... with all the work that we had done to the vortecs on the GTA, it still came out cheaper than a "performace" head, and will still make the power!

Steve

 

Ok guys..........this is a mute point.......kinda tired of people saying how hard it is to make vortecs ready for a "performance" cam, so here is a general price outlay of what I did to mine to make them good to .540 lift, which basically means I can run just about any cam I want:

Comp Cam 88484 (I think thats the #) valve springs- $80

Valve guide seal cutter for use with teflon seals--$40 then sold the tool to the machine shop for $35

Machined for screw in 7/16inch studs: $90

Guideplates: $15

lightweight offset retainers (so that I could up the seat pressure a tad since vortecs have a 1.75 installed height instead of the more usual 1.7): free........traded stock retainers for them from friend

Ok so thats a race ready head for basically the cost of the head plus 190. Granted I got a few things for free or swindled my way into a deal, but doesn't everyone work a deal when your money is on the line?

Yeah I'm gonna get my car to the track, but in case anyone didn't see my post, all the torque/HP just grenaded my RAM clutch in my firebird.........I was planning on going to the track the 13th. Doh!!! If I hook it up and get a 60ft 2.0 or better it has to run 12.5 or better. My friend vadim has (well had, he just parted it out) a 85 trans am with brownsfield polished aluminum heads, solid roller cam and with slicks he was running 12.40's @ 112; and on multiple street races BEFORE I removed my sway bar and some more weight I was pulling away slightly from him in 3rd gear on the top end, so if anything I'll at least run a tenth or two better. Damn, you know whats depressing? I have this feeling that once I get a sticky clutch in................BOOM, there goes the T-5.........then once I get a good tranny in..............BOOM there goes the rearend..............then once I get the...........well you get the point. They should make a smiley face little graphic for the term......MONEY PIT!!

 

Yup, thats exactly where we seem to be with the GTA... low 12's. No time slips on it, and it need to hit up the dyno to get another chip burned up, but its already running great... took out a supercharged 5.0 stang a couple nights ago- Boy was he surprised haha

Steve

 

I agree, the Vortecs are a good performance head. Whether its a truck head or not. What distinguishes a performance head? THe flow, the power potential, or what it comes with? If you buy a SB2.2 bare head, is that a performance head? It doesn't come with springs, studs, valves, locks. Is it a performance head. In my opinion, it is. THere are just items that need added before it becomes useful. The Vortecs are in the same boat. THey just need certain items to make them useful.